Resectability of presymptomatic pancreatic cancer and its relationship to onset of diabetes: A retrospective review of CT scans and fasting glucose values prior to diagnosis

BACKGROUND: The timeline of progression of pancreatic cancer from resectable to unresectable disease is unknown. New-onset diabetes often occurs in pancreatic cancer. It is unclear if the cancer is resectable at the onset of diabetes. We (a) determined the resectability of pancreatic cancer on abdominal CT scans done prior to clinical diagnosis and (b) correlated resectability with onset of diabetes. METHODS: All CT scans done at diagnosis or before pancreatic cancer diagnosis were reviewed and pancreatic changes classified as normal, potentially resectable, or unresectable pancreatic cancer. Fasting blood glucose values obtained at and prior to diagnosis were available in 18 patients. The date of onset of diabetes and the interval between onset of diabetes and diagnosis of cancer were noted. RESULTS: Thirty patients fulfilled inclusion criteria. Prior to diagnosis, 28 patients had 38 CT scans done at a median of 18 months (range 1-41) before cancer diagnosis. At cancer diagnosis, only 7/30 patients could undergo margin-negative surgical resection. CT scans done >= 6 months prior to diagnosis showed either a normal pancreas (N = 20) or a resectable mass (N = 6); none had unresectable cancer. The mean interval between onset of diabetes and diagnosis of pancreatic cancer was 10 months (range 5-29 months). At the onset of diabetes, 3 patients had normal pancreas, 6 had resectable, and 4 had unresectable pancreatic cancer. CONCLUSIONS: Pancreatic cancer is frequently undetectable or resectable on CT scans done >= 6 months prior to clinical diagnosis. At onset of diabetes, pancreatic cancers are generally resectable.